The success that you have with planting your lawn depends on how well the soil is prepared beforehand. Unlike a vegetable or flower garden where the soil can be changed and built up each year, a lawn grows in the same soil year after year. It is very important to prepare your soil so that you can have a healthy lawn from spring through the winter months.
Most nutrient deficiencies can be corrected after the lawn has been established, changing the soil texture under a growing lawn is difficult and quite expensive. The effort spent in preparing the soil will be rewarded by the health and beauty of your lawn for years to come. This is true for seed lawns as well as sod lawns. Even though sod has a little soil already attached, soil preparation is still very important to success.
1. Plan ahead to remove the top 6 inches of soil. Push it off to one side and save it for re-spreading. Remove any debris such as plaster, stones, trash and rocks. Fill in any trenches or depressions with soil and thoroughly settle in by watering.
2. Next, grade the soil. The grade typically is sloped so that water flow is away from your house. Avoid steep slopes. Make gentle and smooth slopes because they look better and are easier to maintain. A 1 to 1½ ft. Drop in 10 linear feet is excellent. For a steeper grade, ground covers other than grass can be used.
3. Find out what kind of soil that you have. There are three principle types of soil: sand, clay and loam. Sandy soil is made up of rather large particles. It drains easily but my lack humus, the organic matter in soil. Clay soils are made up of very fine particles of disintegrated rock. It holds tremendous quantities of water and frequently has poor drainage. Loamy soil is an easily crumbled mixture of different proportions of clay, sand, and organic matter. This is the best soil to have, although not many places would have this soil. This is the ideal soil for lawns.
If yo have sandy, clay soil, there are many things you can do to change the physical characteristics of either one. Soil rebuilding with peat moss and commercial fertilizer is usually cheaper than excavating and refilling with new soil.
4. The best way to improve soil is to mix in as much organic fertilizer as possible. Leaves and grass and compost are best. Peat moss creates an ideal seed bed. Don’t waste humus by mixing it too deep. You only need to stay within 4 to 5 inches deep. If your soil is gravelly or filled with clay, then you will need to bring in some topsoil. Be careful to get only the best quality. Some companies will send you good soil, while others may send you clods of dirt which is a nightmare.
5. If you are putting in seed and have done all the above steps, you should have no problem with seeding. Use a lawn rake to make sure the surface has been leveled out until the surface is smooth. A smooth seed bed will absorb water evenly giving you a uniform germination of any seed and even growth of any grass. If you are planning on putting in a sprinkler system you should do that at this point.